1. Field Of The Invention
The invention relates to a process for the continuous cooling and solidification of metal oxides by continuous casting.
2. Background Of The Invention
A process for the continuous cooling and solidification of metal oxides by continuous casting is known from German Patent No. 1,259,762. In such patent process the metal oxide melt is allowed to run on the peripheral surface of an inwardly cooled roll. The metal oxide melt solidifies there and is fed as a plastic strip through a nip, which is formed between a cooling roller and a press roll. The press roll is placed to be movably perpendicular to the nip and is pressed against the cooling roller by means of a cable line with a weight having a preset pressing force. As a result, the metal oxide strip in the plastic state is separated from the cooling roll and is removed from the peripheral surface of the cooling roll so that it can be conveyed off on a cooled horizontal belt.
Since in such known process the melt is already solidified before running into the nip, no melt accumulation is formed between the rolls, as a result of which also no front sealing elements are necessary. Because of the movability of the press roll perpendicular to the nip, a bearing break is indeed avoided if a very thick material layer solidifies on the cooling roll, but a preset adjustment of the nip is not possible. The product strip achieved with such known process has a greatly fluctuating gage, which has a disadvantageous effect on the uniformity of the abrasive grains obtained from the product strip.
From European Patent Document No. B1 0,057,651 it is known to let metal oxide melts cool and solidify by continuous casting by introducing the melt into the converging space of two inwardly cooled rolls with parallel axes, which rotate in opposite directions as substantially the same peripheral speed. In this case the speed of the rolls and their cooling capacity are regulated so that in the plane of the axis of rotation in the nip between the two outer solidified layers a still liquid film is present. The still liquid film also extends over a small length after the nip. In such known process, a uniform nip is preset so that if a solidified material is pressed through the nip, a bearing or shaft break can occur.